I see this mindset very often. You aren’t the first one to worry about crew casualties. I’m of the opinion that if you’re terrified of casualties, you’ve probably chosen the wrong profession. Exceptions exist: Ace frigate pilots may not be risking their own crew, but they will certainly rack up a body count. I know a pilot who has never fired a shot in her fifteen year career, but she makes a living hauling materials to make warships. Nobody stays in this line of work while keeping their hands completely clean but if going above and beyond the usual assurances for crew safety help to keep your conscience clear, go ahead.
Personally, while I don’t waste lives frivolously, I do undock with a purpose, and I will use the best tool available to accomplish that purpose. Most often that means a crewed vessel. Treat your crews well, try not to waste their lives, and they’ll have the confidence to serve aboard your larger vessels knowing that you’re going to do what you reasonably can to bring them home.